Wednesday , April 21 2021

Ocean waves and winds are getting taller and stronger



During extreme storms, ocean waves may be as high as 20 meters or as high as five-story buildings.

More than being the only product of our time systems, waves are critical for shipping oceans, beach stability, coastal floods or floods, and determining the design of coastal and coastal structures.

Extreme wave conditions are increasing all over the world. Picture: Get pictures

But our new research, published in Science, shows that these waves and the winds they generate are increasing in size and doing so in the last 30 years.

These new measurements show that global mean waves conditions increase, but more importantly, extreme waves conditions increase even faster with the greatest increases occurring in the Southern Ocean.

We found that the extreme winds in the South Ocean increased by about 1.5 meters per second or 8 percent over the last 30 years. Similarly, extreme waves in the same region increased by 30 centimeters or 5 percent. In general, winds are rising faster than the waves.

In addition to the rise of the Southern Ocean, extreme winds have also increased in the equatorial Pacific and Atlantic and North Atlantic for about 0.6 meters per second during the 30-year period.

These changes in the wind of the ocean and the waves are determined by creating and analyzing the satellite measurement of wind speed and wave height.

We used data from a total of 31 satellites that were in orbit between 1985 and 2018. For more than thirty years, these satellites have made approximately 4 billion measurements of wind speed and wave height.

Global trends in the extreme (90th percentile) wind speed (peak) and the height of the wave (down) in the period 1985-2018. Areas that red indicate an increase in values ​​while blue shows a decrease. Picture: delivered

Although the data is huge, be useful all the satellites needed to be very precisely calibrated. This was done by comparing satellite measurements with more than 80 ocean floating vessels all over the world. This is the largest and most accurate database of its kind ever compiled.

More importantly, within the combined database, there are three different forms of satellites – altimeters, radiometers and scatterometers. They used different methods for measuring the waves of the ocean, so their combination provides even more extensive data.

Increasing the height of the extreme wave is less uniform than the winds. Despite the rise of the Southern Ocean, the heights of extreme waves are rising in the North Atlantic. The rate of increase in wind speed and wave height are shown in the graphs above.


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